Radiation levels signal nuclear crisis at Fukushima

On 16 March 1979, Columbia Pictures released a new film starring three of Hollywood’s biggest stars.

The China Syndrome told the tale of a nuclear reactor accident in California, threatening to trigger a meltdown of the reactor’s radioactive core that would cause it to melt through the containment vessel into the earth below, threatening a massive radiation release as the superheated uranium made contact with the groundwater below.

On 28 March 1979, just 12 days later, a reactor at Pennsylvania’s Three Mile Island plant suffered a partial meltdown, the nation’s first highly publicized reactor accident [although, as we have notedbefore, a potentially far worse disaster had happened in California twenty years earlier], sending ticket sales soaring.

And now, as new evidence of soaring radiation and a hole in one of the reactors at Japan’s Fukushima-Daiichi reactor complex [previously] is making The China Syndrome look more like prophecy that just a simple Hollywood blockbuster.

Radiation levels inside a damaged reactor at the Fukushima Daiichi nuclear power station are at their highest since the plant suffered a triple meltdown almost six years ago.

The facility’s operator, Tokyo Electric Power (Tepco), said atmospheric readings as high as 530 sieverts an hour had been recorded inside the containment vessel of reactor No 2, one of three reactors that experienced a meltdown when the plant was crippled by a huge tsunami that struck the north-east coast of Japan in March 2011.

The extraordinary radiation readings highlight the scale of the task confronting thousands of workers, as pressure builds on Tepco to begin decommissioning the plant – a process that is expected to take about four decades.

The recent reading, described by some experts as “unimaginable”, is far higher than the previous record of 73 sieverts an hour in that part of the reactor.

A single dose of one sievert is enough to cause radiation sickness and nausea; 5 sieverts would kill half those exposed to it within a month, and a single dose of 10 sieverts would prove fatal within weeks.

Robot finds evidence the core escaped the reactor

And now for the China Syndrome angle.

There’s clear evidence the core melted through the containment vessel.

Tepco also announced that, based on its analysis of images taken by a remote-controlled camera, that there is a 2-meter hole in the metal grating under the pressure vessel in the reactor’s primary containment vessel. It also thinks part of the grating is warped.

The hole could have been caused when the fuel escaped the pressure vessel after the mega-quake and massive tsunami triggered a station blackout that crippled the plant’s ability to cool the reactors.

The searing radiation level, described by some experts as “unimaginable,” far exceeds the previous high of 73 sieverts per hour at the reactor.

Tepco said it calculated the figure by analyzing the electronic noise in the camera images caused by the radiation. This estimation method has a margin of error of plus or minus 30 percent, it said.

An official of the National Institute of Radiological Sciences said medical professionals have never considered dealing with this level of radiation in their work.

The latest discovery spells difficulty in removing the fuel debris as part of decommissioning work at the plant. The government and TEPCO hope to locate the fuel and start removing it from a first reactor in 2021.

The debris is believed to have been created as nuclear fuel inside the reactor pressure vessel overheated and melted due to the loss of reactor cooling functions.

In the coming weeks, the plant operator plans to deploy a remote-controlled robot to check conditions inside the containment vessel, but the utility is likely to have to change its plan.

For one thing, it will have to reconsider the route the robot is to take to probe the interior because of the hole found on the grating.

Also, given the extraordinary level of radiation inside the containment vessel, the robot would only be able to operate for less than two hours before it is destroyed.

That is because the robot is designed to withstand exposure to a total of up to 1,000 sieverts of radiation. Based on the calculation of 73 sieverts per hour, the robot could have operated for more than 10 hours, but 530 sieverts per hour means the robot would be rendered inoperable in less than two hours.

And to conclude,. . .

Lest you be worried,, here’s a little cheering up in the form of an full page advertisement from Newsweek, published way back on 12 October 1964: